This article examines an understudied aspect of Guatemala's Cold War counter-insurgency campaign: the concerted effort to destroy the seeds of oppositional thinking by criminalizing any and all forms of dissent, both during wartime and since. It explores the lasting effects of this stigma on contemporary Guatemalan society and analyzes the work being done by a tenacious group of activists attempting to reverse that stigma in laboring to rescue and make use of a voluminous, recently discovered cache of once-secret police archives. By marshaling documentary evidence of crimes against humanity committed by state security forces, the activists and war survivors are toiling in the archives with an eye to the future: they hope to achieve not only criminal justice for the past, but also the broader reivindicación, or rehabilitation, of critical thinking and collective social action.